Materials Data on K2B4O7 by Materials Project

K2B4O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 3-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.75–3.34 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.70–3.00 Å. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.69–3.13 Å. In the fourth K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.69–2.91 Å. There are eight inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.37 Å) and two longer (1.39 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.37 Å) and two longer (1.38 Å) B–O bond length. In the third B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.37–1.39 Å. In the fourth B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.37–1.39 Å. In the fifth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.51 Å. In the sixth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.52 Å. In the seventh B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.46–1.51 Å. In the eighth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.51 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two K1+ and two B3+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to three K1+ and two B3+ atoms. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two K1+ and two B3+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to three K1+ and two B3+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two B3+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two K1+ and two B3+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+ and two B3+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+ and two B3+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to three K1+ and two B3+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+ and two B3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+ and two B3+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two B3+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+ and two B3+ atoms. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two B3+ atoms.